One of the most important features that distinguish reading from listening is the nature o

f the audience.【C1】______the writer often does not know who will read what he writes, he must【C2】______to be as clear as possible. Time can be taken to plan the piece of writing so that it is eventually organized into some sort of【C3】______sequence of events or ideas. When we speak, however, we normally have very【C4】______time to plan what we intend to say.【C5】______, we may begin speaking before we【C6】______what to say. Our thoughts then tumble out in【C7】______a logical sequence. Since we are actually【C8】______our audience face to face we may omit some of the information we believe our audience shares.【C9】______the more familiar we are with out audience, the more information we are likely to leave out. In any【C10】______they can always stop and ask a question or ask for clarification if we have left out too much. A reader, however, cannot do【C11】______but can at least attempt comprehension at his own speed;【C12】______, he can stop and go backwards or forwards,【C13】______to a dictionary or just stop and rest. When we listen we may have to work hard to sort out the speaker' s【C14】______by refer ring backwards and forwards while the speaker continues. As the speaker struggles to organize his thoughts, he will use filler phrases to give him time to plan.【C15】______these fillers, he will still make mistakes and repeat what he has already said. His speech will be characterized【C16】______a limited range of grammatical patterns and vocabulary and the use of idioms to【C17】______some general meaning quickly. It should be clear, then, that the listener has to take an active【C18】______in the process by ignoring the speaker' s repetitions and mistakes, and by seeking out the main idea information through recall and prediction. To keep the process going【C19】______he also has to inform. the speaker that he has understood【C20】______actually interrupting.

【C1】

A．However

B．Since

C．Although

D．Unless